Automatic electric signaling mechanism



R. E. TOWNSEND, JR

AUTOMATIC ELECTRIC SIGNALING MECHANISM Filed May 20, 1955 Fig.1..

invenfm". 38 Robefl ETownsend UT.

' byfiflaMWfi W AWys.

Patented June 9, 1936 PATENT OFFICE AUTOMATIC ELECTRIC SIGNALING MECHANISM Robert E. Townsend, Jr., Boston, Mass.

Application May 20,

4 Claims.

This invention relates to improvements in automatically operable signaling mechanism, and. one of the objects thereof is to provide a thermostatically controlled signaling mechanism with 5 means for periodically actuating an audible signal when the temperature, to which the thermostatic means is subjected, remains above or below a predetermined standard of temperature, or more accurately above or below a narrow predetermined range of temperature varying, for example, from one to three or more degrees from said predetermined standard.

A further object of the invention is to provide thermostatically operable signaling mechanism having a periodically operated audible signaling mechanism of the character above described, with visible signaling mechanism preferably operable continuously during the prevalence of a temperature varying from the predetermined standard or range of temperature.

A further object of the invention is to provide signaling mechanism of the character above described containing a thermostatically controlled periodic audible signaling mechanism and visible E signaling mechanisms selectively operable to indicate substantially continuously the prevalence of temperature above or below the predetermined standard or range of temperature.

A further object of the invention is to provide a signaling mechanism of the character described in which the visible signaling mechanism comprises lights of different color, with means operable in conjunction with the actuation of the audible signaling mechanism momentarily to interrupt the electric circuit through the active light, thereby to call attention more pointedly to the condition of the prevailing temperature.

A further object of the invention is to provide a portable signaling device of the character above described which can be connected to the outlet of the electric service lines in any room.

7 These and other objects and features of the invention willmore fully appear from the following description and the accompanying drawing, andwill be particularly pointed out inthe claims. T In the drawing:

Fig. l is a diagrammatic view of an electric signaling system embodying the invention;

' Fig. 2 is a detail view of a modified formof thermostatic mechanism for controlling the electric circuits of said signaling mechanism; and,

Fig. 3 is. a view of a portable signaling device embodying the invention. g m

. The electric-signaling system illustrated in the accompanying drawing is adapted to be supplied 1933, Serial No. 672,010

with current from a usual service line of 110 or 220 volt current, with a suitable transformer for reducing the voltage of the current and consequently increasing the amperage thereof to that which may be employed in the operation of usual types of audible signaling mechanism, such as a bell or buzzer, and visible signaling mechanism, such as electric lights, or other means for visually indicating the prevailing condition of temperature with respect to a predetermined standard or range of temperature.

The invention is particularly designed for use in enclosures, such as school rooms, factories, auditoriums, and the like, in which the temperature and ventilation are not automatically controlled, but also may be used in connection with automatically controlled heating and/r ventilating systems for the purpose of more accurately checking the temperature condition of the enclosure.

The invention is also adapted for use in connection with apparatus in which it is necessary or desirable to maintain a substantially constant temperature under the supervision of an operator.

In the preferred embodiment of the invention illustrated in the drawing, the electric current is supplied through service lines I and 2 from any suitable source of power to the primary 3 of a transformer, the secondary 4 of which supplies the current of proper voltage through a main circuit comprising a conductor 5 and a bi-lateral contact member 6 of a thermostatic switch. The thermostatic switch comprises a thermostatically operated arm I which extends between conductor arms 8 and 9 of branch circuits having respectively contact members it] and I I forming the terminals of conductors l2 and 13 containing respectively visible signaling means and which join with a common conductor leading tothe opposite end of the secondary of the transformer. The conductor E2 of the branch circuit leads to an electric signaling device, preferably an electric light [4 of a distinctive color; such as red, and from said electric light through a conductor l5 to a switch member l0 which normally is in contact with a complementary switch member I! from which a conductor l3 leads to the opposite end of the secondary from that to which the conductor 4 is connected. The conductor [3 of the other branch circuit similarly leads to a visible signal I9, such as a light of another distinctive color, for example green, from which a conductor leads to and is connected with the conductor l5 aforesaid.

The thermostatically operated arm I, as illustrated in Fig. 1 of the drawing, is in the form of a lever, the lower end of which is mounted upon an adjustable fulcrum 2i, preferably in the form of a nut mounted upon an adjusting screw 22 having at one end a milled head 23 and rotatably mounted at the opposite end in a suitable rigid support 24 secured to the frame-work of the mechanism.

The lever I is actuated by a thermo-sensitive means, such as a container or a battery of containers 25 having flexible walls and filled with an expansible fluid, such as ethyl chloride. A rod or bar 26, connected to the thermo-expansible members, is pivotally connected to the lever I at a suitable distance from the fulcrum 2| By rotating the milled head 23 of the adjusting screw 22, the upper end of the lever I may be positioned midway of the terminals If! and l I for any predetermined standard of temperature. If the temperature, to which the thermostatic member is subjected, increases from said predetermined temperature, the upper end of the arm I will be moved to the right, thereby engaging the terminal I9 and forcing it into engagement with the conductor arm 8, thereby completing the circuit through the branch I2, and signal Id, the conductors I5 and I6 and I8, to the sec ondary of the transformer, thus energizing the signaling mechanism M, such as a red electric light, and maintaining the same in continuous operation so long as the arm 'I retains the terminal Ill in contact with the conductor arm 8, thus visually indicating that the temperature is above the predetermined desired temperature or range. Upon falling of the temperature within the predetermined range, the arm I will be moved out of contact with the terminal I0, thereby permitting its disengagement from the conductor arm 8, thus breaking the branch circuit and discontinuing the visible signal.

If, on the other hand, the temperature to which the thermostatic means is subjected decreases below the predetermined standard, the arm I will be swung in the opposite direction, toward the left, thereby forcing the terminal II to contact with the arm 9, thus completing the circuit through the conductor I3 of the other branch circuit, the signaling device I9, such as a green light in said circuit, and thence through the conductors 20, I5, I6, and I8, to the secondary of the circuit, thus visually indicating that the temperature is below the predetermined range of temperature.

The actuation of the lever arm I in the manner aforesaid to complete either of the branch circuits containing the visible signal also acts to energize an auxiliary circuit containing an audible signaling mechanism, such as a bell, buzzer, or the like. This auxiliary circuit comprises a conductor 21 which is connected to the lever arm I and extends to a terminal 28 of the electric mechanism for actuating the audible signal, such as a bell 29. The opposite terminal 30 of the audible signaling mechanism is connected to a conductor 3! which leads to the terminal 32 of a normally open switch. The movable switch arm II, which constitutes one of the members of the main circuit, is adapted to be periodically actuated to engage the terminal 32 by suitable clock mechanism contained in a casing 33 and which operates a shaft 34 having secured to it suitable means, such as a disk 35, having a projection or cam 35 adapted to engage the end of the switch arm I! and remove the switch arm I! from contact with the terminal I6 and cause its engagement with the terminal 32, thereby completing the circuit through the audible signaling mechanism to cause a single stroke of the bell, or a short actuation of a buzzer, or other signaling device. As soon as the projection or cam 36 passes out of engagement with the end of the switch member II it will be disengaged from contact with the terminal 32 and again returned by suitable spring mechanism into engagement with the terminal It.

By reason of this construction therefore the audible signaling mechanism will be actuated upon each revolution of the shaft 34 to cause a single stroke of the bell at predetermined regular intervals. Concurrently with the actuation of the audible signaling mechanism the circuit through the active visible signaling device will be momentarily interrupted thereby calling attention more pointedly to the active visible signal.

It will therefore be obvious that the invention above described is adapted to produce periodical short signals calling attention to the fact that the temperature has varied from the predetermined standard of temperature and the visible signal indicates to the observer whether the temperature is above or below the predetermined standard, so that such observer may make proper adjustments of the heating mechanism, or of the ventilating mechanism to restore the temperature to the predetermined standard, or within a predetermined narrow range from said standard.

The invention is particularly useful in school rooms and the like where the instructor is chargeable with maintaining proper conditions of temperature and ventilation. The periodic strokes of the audible signaling mechanism which may occur every few seconds or every minute will definitely call the instructors attention to the temperature condition of the room, so that proper adjustment of heating or ventilation may be made and without serious disturbance to those within the room.

The usefulness of the invention in connection with other enclosures, and for signaling the variations in temperature from a desired standard of temperature in apparatus in which it is desired to maintain a substantially constant standard of temperature, is obvious.

In Fig. 2 of the drawing a modified construction is shown in which the thermostatic mechanism comprises a bi-metallic thermostatic element 31, the upper end of which extends between the terminals I6 and I I of the branch circuits containing the visible signaling mechanism, and is adapted I upon movement, either to the right or to the left, to cause the respective terminals to engage the conductor members 8 and 9 of the bi-lateral member 6 of the main circuit. In this construction the opposite end of the bi-metallic thermostatic member is fixedly secured to a shaft 38 mounted in a suitable rigidly supported bearing and having sufficient frictional engagement therewith to maintain it in any adjusted position. The shaft 38 may be provided with an index arm 39 adapted to be moved over a suitable scale 40 which may be calibrated to indicate the position at which the arm 31 will be set midway of the terminals I0 and II, or any desired predetermined standard of temperature within said range.

In this construction the fiexure of the bimetallic thermostatic member 31 produced by increase in temperature will cause the upper end thereof to force the terminal I0 into engagement with the conductor arm 8, thereby completing the branch circuit through the visual signaling .device l4, while decrease in temperature below the predetermined standard will cause fiexure of the thermo-sensitive member 31 in the opposite direction to force the terminal ll into contact with the conductor arm 9, thus completing the branch circuit through the visible signaling device I9. The conductor 2'! of the branch circuit containing the audible signaling mechanism desirably is connected to the shaft 33 of the bimetallic member t'i and upon completion of the circuit through either of the conductor arms 8 and 9 will complete the circuit through the audible signaling mechanism to the switch terminal 32, so that the actuation of the switch member IT by the projection 36 upon the disk 35 will cause the'switch member ll to engage the terminal 32 temporarily, thereby completing the circuit through the audible signaling mechanism, thereby periodically actuating the same in the manner aforesaid.

It will be understood that the invention above described comprises both visible and audible signaling mechanism operable to indicate variations in temperature from a predetermined standard or narrow range of temperature, and that either the visible or the audible signaling mechanism may be independently employed, or that a single visible indicating mechanism may be used instead of a plurality;

In Fig. 3 of the drawing a compact portable signaling device embodying the invention is illustrated which comprises a small portable casing 4| which may desirably be of the general configuration of a clock casing and in which the various mechanisms of the signaling device may be mounted. Desirably the clock mechanism is electrically actuated and the current supplied thereto by branch conductors 32 and 43 from the service lines I and 2. A switch it, may be provided either in the service lines or preferably in the common conductor leading from the secondary of the transformer to the thermostatically operated switch, (see Fig. 1) and the switch may be operated by a knob it, or other manual device extending through the casing, as illustrated in Fig. 3.

It will be understood that the particular embodiment of the invention specifically described herein is of an illustrative character and is not restrictive, and that various changes may be made in construction, arrangement of parts, mechanisms or circuits, within the spirit and scope of the following claims.

Having thus described the invention, what is claimed as new, and desired to be secured by Letters Patent, is:

1. Automatically operable signaling mechanism comprising a main circuit having visible signaling means, a thermostatically operable switch in said main circuit maintained normally in open position. during a predetermined narrow range of temperature from a predetermined standard and maintained in closed position when the temperature increases above said range, thereby causing continued actuation of the energized visible signal, an auxiliary electric circuit having said thermostatic switch therein provided with audible signaling mechanism, and means for momentarily breaking said main circuit and closing said auxiliary circuit thereby momentarily actuating the audible signal and momentarily discontinuing the visible signal.

2. Automatically operable signaling mechanism comprising a main circuit having two branches containing respectively diiferent visible signaling 5 means, a bi-lateral thermostatically operable switch in said main circuit maintained normally in open position during a predetermined narrow range of temperature from a predetermined standard of temperature operable selectively to close the circuit through one or the other of said branches when the temperature increases above or decreases below said range thereby causing continued actuation of the energized visible signal, an auxiliary electric circuit having said thermostatic switch therein and provided with audible signaling mechanism, and a switch in said main and auxiliary circuits normally closing the main circuit and opening the auxiliary circuit, and means acting intermittently on said switch momentarily to open the main circuit and concurrently to close the auxiliary circuit whereby when the main circuit is closed through either branch the momentary actuation of said audible signal and the flashing of the energized visible signal will be eifected.

3. Automatically operable signaling mechanism comprising a main electric circuit having two branches each having a visible signal different from the other and an auxiliary circuit having an audible signal therein, an intermittently operable switch common to said circuits normally closing said main circuit and opening said auxiliary circuit, a thermostatically actuated switch arm in said main circuit normally maintained within a predetermined range from a standard temperature out of contact with oppositely disposed terminals in the respective branches containing the visible signals, but selectively operable by rise or fall in temperature beyond said predetermined range to engage the selected terminal and thereby energize the visible signal in the branch through which the current passes, and means for periodically actuating said intermittently operable switch momentarily to open said main circuit and concurrently to close said auxiliary circuit.

4. Automatically operable signaling mechanism comprising a main electric circuit having two branches each having a visible signal different from the other and an auxiliary circuit having an audible signal therein, an intermittently operable switch common to said circuits normally closing said main circuit and opening said auxiliary circuit, a thermostatically actuated switch arm in said main circuit forming a switch arm normally maintained within a predetermined range from a standard temperature out of contact with oppositely disposed terminals in the respective branches containing the visible signals, but selectively operable by rise or fall in temperature beyond said predetermined range to engage the selected terminal and thereby energize the visible signal in the branch through which the current passes, means for periodically actuating said intermittently operable switch momentarily to open said main circuit and concurrently to close said auxiliary circuit, and means for adjusting said thermostatically actuated switch arm relatively to the terminals for the respective branches to adjust the predetermined standard of temperature.

ROBERT E. TOWNSEND, JR. 

